It could be probably a bug on iOS7. But the last button is not separated from the previous one
I found a way to make it work on iPhone and iPad in the least hacky way:
I assume that the missing separator is caused by the cancel button not being recognized as a separate case when adding it first or through the init.
I think ActionSheet requires a cancel button.So you can add the cancel button title.
Another way is: Specify actionSheet's cancelButtonIndex.
For example,in your case, you can add a "Cancel" in otherButtonTitles at index 4 and then specifiy actionSheet.cancelButtonIndex = 4.